An internationally recognized water and climate change expert admitted yesterday that he lied about his identity to obtain internal funding and strategy documents from the Heartland Institute.

Writing in The Huffington Post, Pacific Institute President Peter H. Gleick apologized and called his actions "a serious lapse of my own professional ethics and judgment." But he also said his decision to fraudulently acquire and then leak a set of explosive documents from the conservative, climate skeptic think tank was prompted by sustained attacks from climate deniers.

"My judgment was blinded by my frustration with the ongoing efforts -- often anonymous, well-funded and coordinated -- to attack climate science and scientists and prevent debate, and by the lack of transparency of the organizations involved," he wrote.

The leak of the Heartland memos -- including a disputed one purporting to outline a strategy to pay a Department of Energy contractor to prepare school curriculum teaching children that the science behind man-made global warming is unsettled -- rocked the climate world last week when they were released to bloggers.

Heartland officials early on acknowledged that it accidentally released several of the memos to someone claiming to be a member of its board of directors. It maintains the "climate strategy" memo is a fraud, calling it "totally fake and intended to defame and discredit the Heartland Institute."

Gleick yesterday denied authorship of that memo. He said he received it in the mail in 2012. "I do not know the source of that original document, but I assume it was sent to me because of my past exchanges with Heartland and because I was named in it," said the scientist who has sparred often with Heartland and others who do not believe in the scientific underpinnings of man-made global warming.

He maintained the quest to verify it led him to trick the Heartland Institute into giving out more information.

Denies altering document
"I attempted to confirm the accuracy of the information in this document. In an effort to do so, and in a serious lapse of my own and professional judgment and ethics, I solicited and received additional materials directly from the Heartland Institute under someone else's name. The materials the Heartland Institute sent to me confirmed many of the facts in the original document, including especially their 2012 fundraising strategy and budget," he added.

"I forwarded, anonymously, the documents I had received to a set of journalists and experts working on climate issues. I can explicitly confirm, as can the Heartland Institute, that the documents they emailed to me are identical to the documents that have been made public. I made no changes or alterations of any kind to any of the Heartland Institute documents or to the original anonymous communication," he said.

Heartland Institute President Joseph L. Bast released a statement late last night saying Gleick's "mere apology is not enough to undo the damage," and indicated likely legal action. He cast doubt on Gleick's claim that he distributed but did not write the disputed strategy memo.

"We hope Gleick will make a more complete confession in the next few days," he said in the statement. "We are consulting with legal counsel to determine our next steps."

Meanwhile, opinion in the blogosphere last night was sharply divided, even among environmentalists. Scott Mandia, founder of the Climate Science Legal Defense Fund spent the morning tweeting that Gleick "has effectively caught Heartland squarely in the headlights."

Others called Gleick a hero for his deception, noting that no one has yet come forward to acknowledge a role in the 2009 theft of climate scientist emails in an incident now widely referred to as 'Climategate.' The blog that published the Heartland Institute memos obtained by Gleick said he "deserves our gratitude" for stealing them.

Others said Gleick's ethical lapse will and should permanently damage the renowned scientist. Richard Klein, climate policy analyst at the Stockholm Environment Institute, wrote: "Irrespective of credentials, a scientist who lets his personal convictions blur his professional judgment is a bad scientist."